Silver halide emulsions containing supersensitizing dye combinations



EXPOSURE STEP March 11, 1969 JONES ETAL 3,432,302

SILVER HALIDE EMULSIONS CONTAINING SUPERSENSITIZING DYE COMBINATIONS Filed May 24, 1965 LONG WAVELENGTH EDGE OF SPECTROGRAMS CURVE IDYE xx 3 CURVE 2-0YE xx+ DYE c N CURVE 3- DYE xx+ DYE B wx 2 CURVE 4- DYE xx+ DYE A CURVE 5- DYE xx+ DYE z I WAVE LENGTH m ,1

JEAN E- JONES NORMAN W- KALENDA INVENTORS ATTORNEY AND AGENT United States Patent 3,432,302 SILVER HALIDE EMULSIONS CONTAINING SUPERSENSITIZING DYE COMBINATIONS Jean E. Jones and Norman W. Kalenda, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N .Y., a corporation of New Jersey Filed May 24, 1965, Ser. No. 458,067 U.S. Cl. 96-104 20 Claims Int. Cl. G03c 1/28 ABSTRACT OF THE DISCLOSURE Photographic silver halide emulsions used in photographic elements are advantageously supersensitized by combinations of a chain substituted cyanine dye with a holopolar carbocyanine dye having a 4,5-dihydro-2-(1H)naphtho[1,2-d]thiazole nucleus and a naphtho[1,2-d]thiazole nucleus with a 5- to 6-membered acidic heterocyclc nl1- cleus as the holopolar group.

/ This invention relates to photographic silver halide emulsions containing certain cyanine dyes, and in particular to supersensitizing combinations therewith of certain holopolar carbocyanine dyes.

It is known in the art of making photographic emulsions that certain dyes of the cyanine class alter the sensitivity of photographic emulsions of the gelatino-silver-halide kind, when the dyes are incorporated in the emulsions. o It is also known that the sensitization produced by a given dye varies somewhat with the type of emulsion in which the dye is incorporated. Furthermore, the sensitization of a given emulsion by a given dye may be altered by varying the conditions in the emulsion. For example, the sensitization may be increased by increasing the silver ion concentration or decreasing the hydrogen ion concentration (i.e., increasing the alkalinity), or both. Thus, sensitization can be increased by bathing plates, coated with a spectrally sensitized emulsion, in water or in aqueous solutions of ammonia. Such a process of altering the sensitivity of a sensitized emulsion by increasing the silver ion concentration and/or by decreasing the hydrogen ion concentration is commonly called hypersensitization. Hypersensitized emulsions have generally poor keeping qualities.

We have found an advantageous supersensitizing combination of certain cyanine dyes with certain holopolar carbocyanine dyes that sensitize silver halide emulsions to shorter wavelengths in the red region of the spectrum and also do not extend too far into the red region as compared with related supersensitizing dye combinations.

It is, accordingly, an object of our invention to provide photographic silver halide emulsions containing certain cyanine dyes and in combination therewith, certain holopolar carbocyanine dyes, that are of particular advantage in applications where for good color reproduction the required sensitization does not extend too far into the red region of the spectrum. Another object is to provide a means for preparing such su ersensitized emulsions. Other objects will become apparent from a consideration of the following description and examples.

The cyanine dyes useful in practicing our invention include those dyes represented by the following formula:

wherein d, m and n each represents a positive integer of from 1 to 2, R and R each represents an alkyl group of 3,432,302 Patented Mar. 11, 1969 from 1-12 carbon atoms, e.g., methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, decyl, dodecyl, p-hydroxyethyl, 'y hydroxypropyl, p methoxyethyl, fl-ethoxyethyl, allyl, benzyl, [5' phenylethyl, ,B-sulfoethyl, 'y-sulfopropyl, -sulfobutyl, carboxymethyl, ,B-carboxyethyl, -y-carboxypropyl, B-acetoxyethyl, carbomethoxyethyl, fl-carbethoxyethyl, etc., R represents a hydrogen atom, an alkyl group of from 1-4 carbon atoms, e.g., methyl, ethyl, etc., an aryl group, e.g., phenyl, p-tolyl, o-tolyl, naphthyl, etc., a heterocyclic group, e.g., Z-pyrryl, 3-pyrryl, 2-indolyl, 3- indolyl, 2-thienyl, 3-pyridyl, 4-pyridyl, or an anilino group; R and R each represents a hydrogen atom, or each of R and R taken together represent a divalent alkylene group having from 2 to 3 carbon atoms in the chain, e.g., an ethylene or trimethylene group, said group completing a 5- or 6-membered heterocyclic ring, or R and R together represent a divalent alkylene group having 3 carbon atoms in the chain, e.g., a trimethylene group, said group completing a carbocyclic ring, or R and R taken together represent a divalent aryl group, eg an o-phenylene group, said group completing a carbocyclic ring, X represents an acid anion, e.g., chloride, bromide, iodide, thiocyanate, sulfamate, methyl sulfate, ethyl sulfate, perchlorate, p-toluenesulfonate, etc., and Z and Z each represents the nonmetallic atoms required to complete a heterocyclic nucleus, especially a 5- or 6-membered heterocyclic nucleus, and particularly a 5- to 6- membered heterocyclic nucleus selected from the class comprising a thiazole nucleus (e.g., thiazole, 4-methylthiazole, 4 phenylthiazole, S-methylthiazole, S-phenylthiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4-(2- thieny1)thiazole, etc.), a benzothiazole nucleus (e.g., benzothiazole, 4-chlorobenzothiazole, S-chlorobenzothiazole, 6 chlorobenzothiazole, 7 chlorobenzothiazole, 4-methylbenzothiazole, 5 methylbenzothiazole, 6-methylbenzothiazole, 5 bromobenzothiazole, 6 bromobenzothiazole, 4 phenylbenzothiazole, 5 phenylbenzothiazole, 4-methoxybenzothiazole, S-rnethoxybenzothiazole, 6-methoxybenzothiazole, S-iodobenzothiazole, 6-iodobenzothiazole, 4 ethoxybenzothiazole, 5 ethoxybenzothiazole, tetrahydrobenzothiazole, 5,6 dimethoxybenzothiazole, 5,6-dioxymethylenebenzothiazole, 5 hydroxybenzothiazole, 6- hydroxybenzothiazole, etc.), a naphthothiazole nucleus (e.g., a-naphthothiazole, [3,;3-naphthothiazole, fi-naphtbothiazole, 5 methoxy ,e-naphthothiazole, S-methoxy-flnaphthothiazole, 5 ethoxy-B-naphthothiazo1e, 8-methoxya-naphthothiazole, 7-methoxy-a-naphthothiazo1e, etc.), a thianaptheno-7,6,4,5-thiazole nucleus (e.g., 4'-methoxythianaphtheno-7,6,4,5-thiazo1e, etc.), an oxazole nucleus (e.g., 4-methyloxazole, S-methyloxazole, 4-phenyloxazole, 4,5 diphenyloxazole, 4 ethyloxazole, 4,5-dimethyloxozole, 5 phenyloxazole, etc.), a benzoxazole nucleus (e.g., benzoxazole, 5 chlorobenzoxazole, S-methylbenzoxazole, 5 phenylbenzoxazole, 6 methylbenzoxazole, 5,6 dimethylbenzoxazole, 5 methoxybenzoxazole, 5- ethoxybenzoxazole, 6 chlorobenzoxazole, 6 methoxybenzoxazole, 5 hydroxybenzoxazole, 6-hydroxybenzoxazole, etc.), a naphthoxazole nucleus (e.g., u-napthoxazole, 18,19 naphthoxazole, fi-naphthoxazole, etc.), a selenazole nucleus (e.g., 4 methylselenazole, 4-phenylselenazole, etc.), a benzoselenazole nucleus (e.g., benzoselenazole, 5 chlorobenzoselenazole, 5 methoxybenzoselenazole, 5 hydroxybenzoselenazole, tetrahydrobenzoselenazole, etc.), a naphthoselenazole nucleus (e.g., a naphthoselenazole, 5, 8 naphthoselenazole, B-naphthoselenazole, etc.), a thiazoline nucleus (e.g., thiazoline, 4 methylthiazoline, etc.), a 2-quinoline nucleus (e.g., Z-quinoline, 3-metliyl- 2 quinoline, S-methyl-Z-quinoline, 7-methyl-2-quinoline, 8 methyl-Z-quinoline, 6-chloro-2-quinoline, 8-chloro-2- quinoline, 6 methoxy 2 quinoline, 6-ethoxy-2-quino- 3-sulfoalkylrhodanines (e.g., 3 (2-sulfoethyl)rhodanine, 3-'(3-sulfopropyl)rhodanine, 3-(4-sulfobutyl)rhodanine, etc.), or 3-arylrhodanines (e.g., 3-phenylrhodanine, etc.), etc., a 2(3H)-irnidazo[l,2-a]pyridone nucleus, a 5,7-dioxo-6,7-dihydro-5-thiazolo [3,2-a] pyrimidine nucleus (e.g., 5,7-dioxo-3-phenyl-6,7-dihydro-5-thiazolo- [3 ,2-a] pyrimidine, etc. a 2-thio-2,4-oxazolidinedione nucleus (i.e., a 2-thio-2,4(3H,5H)-oxazoledione nucleus) (e.g., 3-ethyl-2-thio-2,4-oxazo1idinedione, 3-(2-sulfoethyl)-2-thio-2,4-oxazolidinedione, 3-(4-sulfobutyl)-2-thio-2,4-oxazolidinedione, 3- 3-carboxypropyl) -2-thio-2,4-oxazolidinedione, etc.) a thianaphthenone nucleus (e.g., 3-(2H)-thianaphthenone, etc.), a 2-thio-2,5-thiazolidinedione nucleus (i.e., the 2-thio-2,5(3H,4H)-thiazoledione nucleus) (e.g., 3-ethyl-2-thio-2,5-thiazolidinedione, etc.), a 2,4-thiazolidinedione nucleus (e.g., 2,4-thiazolidinedione, 3-ethyl-2,4-thiazolidinedione, 3-phenyl-2,4-thiazolidinedione, 3-a-I1 aphthyl-Z,4-thiazolidinedione, etc. a thiazolidinone nucleus (e.g., 4-thiazolidinone, 3-ethyl-4 thiazolidinone, 3-phenyl-4-thiazolidinone, 3-a-naphthyl-4-thiazolidinone, etc.) a 2-thiazolin-4-one nucleus (e.g., Z-ethylmercapto-2-thiazolin-4-one, 2-alkylphenylamino-2-thiazolin-4-one, 2-diphenylamino-2-thiazolin-4-one, etc. a 2-imino-4-oxazolidinone (i.e., pseudohydantoin) nucleus, a 2,4-imidazolidinedione (hydantoin) nucleus (e.g., 2,4-imidazolidinedione, 3-ethyl-2,4-imidazolidinedione, 3-phenyl-2,4-imidazolidinedione, 3-a-naphthyl-2,4-imidazolidinedione, l,3-diethyl-2,4-imidazolidinedione, 1-ethyl-3phenyl-2,4-imidazolidinedione, l-ethyl-3-a-naphthyl-ZA-imidazolidinedione, l,3-diphenyl-2,4-imidazolidinedione, etc.), a 2-thio-2,4-imidazolidinedione (i.e. 2-thiohydantoin) nucleus (e.g., 2-thio-2,4-imidazolidinedione, 3-ethyl-2-thio-2,4-imidazolidinedione, 3-(4-sulfobutyl)-2-thio2,4-imidazolidinedione, 3-(2-carboxyethyl)-2-thio-2,4-imidazolidinedione, 3-phenyl-2-thio-2,4-imidazolidinedione, 3-u-naphthyl-Z-thio-2,4-imidazolidinedione, 1,3-diethyl-2-thio-2,4-imidazolidinedione, l-ethyl-3-phenyl-2-thio-2,4-imidazolidinedione, l-ethyl-3-a-naphthyl-2-thio-2,4-imidazolidinedione, 1,3-diphenyl-2-thio-2,4-imidazolidinedione, etc. a Z-imidazolin-S-one nucleus (e.g., 2-n-p1'opylmercapto-Z-imidazolin-S-one, etc.),

etc., R R and R7 each represents the same or a different group selected from the hydrogen atom, a lower alkyl group (e.g., methyl, ethyl, propyl, butyl, etc.), a lower alkoxy group (e.g., methoxy, ethoxy, butoxy, etc.), an aryl group (e.g., phenyl, tolyl, etc.), a halogen atom (e.g., chlorine, bromine, etc.), a sulfo group (including ammonium and alkali metal salts thereof), a carboxy group. (including the ammonium and alkali metal salts thereof), an alkoyloxy group (e.g., acetoxy, propionyloxy, etc.), an alkoxycarbonyl group having from 2 to 10 carbon atoms (e.g., methoxycarbonyl, butoxycarbonyl, decoxycarbonyl, etc.), etc. The compounds of Formula IIA wherein W represents the barbituric acid nucleus such as represented by Dyes A, B and C set forth hereinafter are especially eflicacious.

According to our invention, we incorporate with lightsensitive silver halide one or more of the cyanine dyes represented by Formula I above with one or more of the holopolar carbocyanine dyes represented by Formula II above. Our invention is particularly directed to the ordinarily employed gelatino-silver-halide developing-out emulsions. However, our supersensitizing combinations can be employed in silver halide emulsions in which the carrier or vehicle is a hydrophilic colloid other than gelatin, such as, for example, albumin, agar-agar, gum arabic, alginic acid, etc., or a hydrophilic resin such as polyvinyl alcohol, polyvinyl pyrrolidone, a cellulose ether, a partially hydrolyzed cellulose acetate, etc., which has no deleterious effect upon the light-sensitive silver halide.

The dyes of Formula I and Formula II can be employed in the combinations of the invention in various concentrations depending upon the particular emulsion, concentration of the silver halide, particular results desired, etc.

The optimum concentration of an individual sensitizing dye can be determined in a manner Well known to those skilled in the art by measuring the sensitivity of a series of test portions of the same emulsion, each portion containing a different concentration of the sensitizing dye. The optimum concentration of our supersensitizing combinations can, of course, be readily determined in the same manner, by measuring the sensitivity of a series of test portions of the same emulsion, each portion containing different concentrations of the individual dyes in the combination. In determining the optimum concentration for the supersensitizing, combination, it is advantageous to employ, at first, concentrations of the individual dyes less than their optimum concentrations. The concentrations of the individual dyes can then be increased until the optimum concentration of the supersensitizing combination is determined.

The methods of incorporating sensitizing dyes in silver halide emulsions are well known to those skilled in the art and these known techniques are employed in dispersing the cyanine dyes of Formula I, and holopolar carbo-' cyanine dyes, of our invention in the emulsions. These sensitizing dyes can be directly dispersed in the emulsions, or they can first be dissolved in some convenient solvent, such as pyridine, methyl alcohol, acetone, etc. (or mixtures of such solvents), or diluted with water in some instances, and added to the emulsions in the form of these solutions. If desired, the dyes can be separately dissolved in a given solvent and added separately to the emulsion, or they can be dissolved in the same or different solvent and these solutions mixed together before addition is made to the silver halide emulsions. The cyanine dyes of Formula I, and holopolar carbocyanine dyes of Formula II can be dispersed in the finished emulsions and should be uniformly distributed throughout the emulsions before the emulsions are coated on a suitable support, such as paper, glass, cellulose ester film, polyvinyl resin film (e.g., polystyrene film, polyvinyl chloride film, etc.), polyester film, etc. The following procedure has been found quite satisfactory: Stock solutions of the cyanine dyes of Formula I and holopolar carbocyanine dyes are prepared by separately dissolving these dyes in appropriate solvents as described above. Then, to the flowable silver halide emulsion, the desired amount of stock solution of one of the dyes is slowly added while stirring the emulsion. Stirring is continued until the dye is thoroughly incorporated in the emulsion. Then, the desired amount of stock solution of the other dye is slowly added to the emulsion while stirring. Stirring is continued until the second dye is thoroughly incorporated in the emulsion. The supersensitized emulsions can then be coated on a suitable support and the coating allowed to dry. In some instances, it may be desirable to heat the supersensitized emulsion for a few minutes before coating onto the suitable support. The details of such coating techniques are well known to those skilled in the art. The foregoing procedure and proportions are to be regarded only as illustrative. Clearly, our invention is directed to any silver halide emulsion containing a combination of the aforesaid dyes whereby a supersensiiizing effect is obtained.

To difierent portions of the same batch of photographic gelatino-silver-bromoiodide emulsion were added (1) a cyanine dye of Formula I, (2) a holopolar carbocyanine dye of Formula II and (3) a combination of the dyes of (1) and (2). The emulsions were held for a short time at about 50-52 C., coated on a transparent support, chill set and dried. The coatings were then exposed to daylight quality radiation through either a yellow Wratten #16 Filter which transmits substantially no light of wavelength shorter than about 520 m a red Wratten #29 Filter which transmits substantially no light of wavelength shorter than about 610 Ill/L, or a combination of a Wratten #16 Filter and a green Wratten #61 Filter which latter transmits only light of wavelength lying between 480 and 600 m The filter was selected to correspond to the maximum sensitizing region of the particular cyanine dye illustrated. The exposed coatings were then processed for three minutes in a developer having the following composition:

Grams N-methyl-p-aminophenol sulfate 2.0 Hydroquinone 8.0 Sodium sulfite (desiccated) 90.0 Sodium carbonate (monohydrate) 52.5 Potassium bromide 5.0 Water to make one liter.

The speed, gamma and fog for each of the coatings was then measured. The same emulsion batch was used for the coatings of each example, although not all of the examples used the same emulsion batch.

Included among the dyes of Formula I above are the following dye compounds:

Dye No. Compound I 3,3-dimetliyl-9-pl1enyl4,5,4,5'-dibenzothiaearbocyanine bromide.

II. 3,3-dirnethyl-9-ethyl-4,5,4,5-dibenzothiacarbocyanine chloride.

III 3,3 -dietliyl-9-methy1-4,5,4 ,5 -dibenzothiaearboeyanine bromide.

IV Q-ethyl-B,3-dimethyl-pheny1-4,fi-benzothiacarbocyanine p-toluenesulfonate.

V Q-ethyl-I,S-dimethylthia-T-earbocyanine iodide.

VI 3,3'-diethyl-9-(2-thienyl)4,5,4,5'-dibenzothiaearbocyanine p-toluenesulionate.

VII 3,3-dimethyl-9-(4-pyridyl)4,5,4,5'-dibenzotl1iaearbocyanine p-toluenesulfonate.

VIII 3,3-dimethyl-9-N-methylanilino-4,5,4,5-dibenzothiaearbocyanine iodide.

IX 3,3 ,g tariethyl- ,5-benzoselenathiacarbocyanine X 3,3-diethyl-Q-rnethyL-t,5,4,5-dibenzoselenathiaearboeyanine iodide.

XI 3,3-dimethyl-9-ethyl-oxacarbocyanine iodide.

XII 3,3,9-triethyl-5,6,5,6-dibenzooxacarboeyanine ptoluenesulfonate.

XIII 3,3-dimethyl-9-(2-methyl-3-indolyl)-4,5,4,5'-dibenzothiacarboeyanine p-toluenesulfonate.

XI" 5,5-diehloro-3,3, -triethylthiaearbocyanine bromide.

XV 3,3,9-triethyl-5,6,5',6-dibenzothiacarboeyanine ptoluenesultonate.

XVI 9-(2,5-dimethyl-1-phenyl-3-pyrryl)'3,3'dimethyl-4,5,

4,5-dibenzothiacarbocyanine iodide.

XVII 3,3-dimethyl-9-(Z-pyrryl)-4,5,4',5-dibenzothiaearbocyanine p-toluenesullonate.

XVIII 3,3'-diethyl-9-(B-pyridylmethobromide)-4,5,4,5-dibenzothiaearboeyanine bromide.

XIX 3,3-diethyl-9-(3-pyridylethiodide)-4,5,4,5-dibenzothiaearboeyanine iodide.

XX 3,3-dimethyl-5,5,9-triphenylthiaearbocyanine ptoluenesulfouate.

XXI 3,3'diethyl-5,5,Q-triphenylthiaearbocyanine p-toluene sulfonate. 3,3-diethy1-4,5,4,5'-dibenzothiacarbocyanine bromide.

. 3,3'-diethylthiaearbocyanine iodide. 1,3-diethyl-3'phenylbenzimidazolooxacarbocyanino perchlorate.

3,3-diethy1oxaearbocyanine iodide.

1,1-diethy1-2,2'-eyanine iodide. 3,3-diethyl-9-methyl8,IO-o-phenylenethiaearbocyanine iodide XXVIII 3,3-diethyl-8,9-trimethylene-i,5,4,5-dibenzotliiacarboeyaniue iodide.

XXIX 5-ehlor0-3,3-diethyl-8,9-trimethylene-4,5-benzothia carbocyanine iodide.

XXX 3,3 -dimetliyl-9-phenyl-8,IO-o-phenylenetliiaearboeyanine iodide.

Dye No. Compound XXXI 3 ethyl-Q-methyl-3,8-trimethylenethiacarbocyanine bromide. XXXII 3-ethyl-3,8-ethylenc-9-methylthiaearboeyanine bromide. XXXIII 3ethyl-3,S-ethylene-9-pheny1-4,5,4,5'-dibenzothiacarbocyanine iodide. 3,8-(1,3-butylene)-3-ethyl-9-phenyl-4,5,4,5-dibenzothiaearbocyanine iodide XXXV 3,3,2; iitl-Di(1,3butylene)-9-methylthiaearbocyanine XXXVI 9-ethyl-3,8,3,IO-ditrimethylenethiaearboeyanine p-toluenesulfonate.

XXXVII 3,8,3 10-diethylenethiacarboeyanine salt.

XXXVIII 3,3-diethyl-1,IO-trimethyleneuapl1tha[2,3]imidazolothiaearbocyanine iodide.

XXXIX 3,3-diethyl-1,10-ethylene-4,5-benzothianaphtha[2,3]

imidazoloearbocyanine p-toluenesulionate.

XL. 3-ethyl-3 ,IO-trimetliylenethiaearboeyanine iodide.

XLI. 3,8,3,I0-di(1,3-butylene)4,5,4,5-dibenzothiaearbocyanine iodide.

XLII 3,IO-ethylene-fi-phenyl-3,8-trimethyleneoxathiaearbocyanine bromide.

XLIII 3,8,3,l0-ditrimethylene 5,6,5,6-dibenzooxacarbocyanine iodide.

XLIV 8,10-ethylene-3,3-dimethylthiaearbocyanine iodide.

XLV. 3-ethyl-3 ,IO-ethyleneoxathiaearboeyanine iodide.

XLVI. 3-ethyl-3,IO-ethyleuethiacarbocyanine iodide.

XLVII 3,8-(1,3-butylcne)-3-ethyl-4,5-benzooxathiaearbocyanine iodide.

XLVIII 3-ethyl-3,8-trimethylene-5,6-benzooxathiaearbocyanine iodide.

Included among the dyes of Formula II above are the following typical dye compounds.

Dye No.

Compound J 1,3-diethy1-5[1,3-bis(Iethyl-4,5-dihydro-2(lH)-napl1tho- [1,2-d]selenazolylidene)isopropylidene1-barbituric acid. K. 1,3-diethyl-5-[l,3-bis(1-ethyl-4,5-dihydro-2(1H)-napht,l1o-

[1,2-d]thiazolylidene)isopropylidenel-barbituric acid.

The following examples further illustrate our invention.

Example 1 A silver bromoiodide emulsion was made of the type described by Trivelli and Smith, Phot. Journal, vol. 79, 330 (1939). The melted emulsion was divided into separate portions to which were added a solution of the dye sensitizers I, A, B, C and combinations of I with A, B and C as indicated in Table 1. Each portion was digested at 50 C. for 10 minutes, coated on a film support and dried. The dried samples were given identical exposure through a Wratten #29 filter on an Eastman Sensitometer (Type 1B) for A second to a tungsten light source and processed for three minutes in the above mentioned developer solution, fixed in a conventional sodium thiosulfate fixing bath, washed and dried. Densitometric measurements were made of the developed images on each coating. The relative speed values were calculated on an arbitrary relative speed of for the coating sensitized with 0.08 g. of Dye I per mol. of silver halide, and the gamma values determined. These values along with the fog values are shown in Table 1 below.

wavelengths by use of Dyes A, B and C containing the 4,5-dihydro-p(ot or B,,8)-naphthothiazole nucleus.

Example 6 Coatings were made as in Example 1, excepting that dye sensitizers XXII to XLVIII and A and combinations of A with these others, were used. These coatings were exposed through a Wratten #16 Filter (Table 6) or through a Wratten #29 Filter (Table 7) as indicated in the tables, processed and the relative speed (based on 100 for Dyes XXII, XXXII, XXXVII and XXXVIII), gamma and fog values determined. The results obtained are listed in the following Tables 6 and 7.

TABLE 6 Dye and concentration Relative Gamma Fog (g./n1ol. silver halide) speed 100 1. 72 06 135 1. 63 06 35. 5 1. 44 .00 78 1. 52 06 4 1. 63 05 44 1. 58 04 3 1. 50 06 55 1. 57 .04 23 1. 34 .06 155 1. 40 07 XX II (0.08) 13. 2 1.61 06 XXVII (0.08) +11 (0.02) 118 1. 53 06 XXVIII (0.08) 25 1. 38 06 XXVIII (0.08) +11 (0.02) 34 1. 35 05 XXIX (0.08) 8. 7 1.14 05 XXIX (0.08)+A (0.02)- 27 1.44 .04 XXX (0.08) 38 1.70 .06 XXX (0.08)+A (0.02) 58 1. 97 .06 XXXI (0.08) 132 1. 37 'XXI (0.08)-H1 (0 02)- 251 1. 64 (0.08) 9. 5 1. 58 .06 XXXIII (0.08) 87 1.79 .06 XXXIV (0.08) 50 1. 60 06 XXXIV (0.08)+A (00 182 1.68 06 XXXVI (0.08 67 1. 54 06 XXXVI (0.08)+A (0.02)- 91 1. 40 06 A (0.02) Too small to measure 06 0. 96 16 0.91 1. 07 07 1. 12 06 1. 14 1. 20 06 1. 36 12 1. 53 10 XLV 37 1.18 .14 XLV (0.08) +A (0.02) 871 1. 43 .04 XLVII (0.08) 257 1.15 06 XLVII (0.08)+A (0.02) 550 1. 26 06 A (0.02) Too small to measure .06

TABLE 7 Dye and concentration Relative Gamma Fog (g./mol. silver halide) speed XXXII (0.08) 100 1. 31 .06 XXXII (0.08)-l-A (0.02) 417 1. 77 .06 XXXV .0 1. 54 00 XXXV (0.08) +A (0.02) 110 1. 31 04 A .0 None .06 XXXVIII (0.08) 100 1. 28 06 XXXVIII (0.08)+A (0.02) 832 0.92 06 XX IX .0 1,290 1. 28 24 XXXIX (0.08) +A (0.02) 2, 090 1. 55 10 XL .0 331 0. 90 .08 631 1. 02 06 6. 3 0. 90 12 316 1. 20 07 LVI (0.08) 479 1. 30 07 XLVI (0.08)+A (0.02) 1,100 1. 57 .06 XLVIII (0.08) 11. 0. 94 .06 XLVIII (0.08)+A (0 0.95 .02

It Will be noted that the supersensitizing combinations listed in Tables 6 and 7 above, show in each case of comparison substantially higher relative speeds than do the individual Dyes XXII to XLVIII.

Further evidence that the supersensitizing dye combinations of the invention result in sensitizing to shorter wave-lengths in the red region of the spectrum is furnished by the accompanying graphs derived from long wavelength cut-off of the respective spectrograms. The wavelength at which density reaches 0.3 is plotted for each exposure step. These steps differ by 0.3 log E with Step 1 being that of the greatest exposure. Referring to FIG. 1 and specifically to Step 1, it will be noted that comparison dye combination XX+Z has the value 12 691 mu, whereas XX-l-A, XX+B and XX+C dye combinations of the invention have the substantially lesser wavelength values of 679 m and 671 m 674 my, respectively. Dye XX by itself has the value 668 III/.L. The respective curves are substantially parallel with each other in their lengths.

The immediate sensitizing dye combinations provide a valuable technical advance because of their desirable spectral sensitizing effects and particularly because of the shift of the A max. values to shorter wavelengths as illustrated by the drawings.

The cyanine dyes coming under Formula I above include many well known dyes. Such dyes can advantageously be prepared in accordance with the processes of a number of patents such as Brooker US. Patent 1,861,836, issued June 7, 1932; Brooker US. Patent 1,934,657, issued Nov. 7, 1933; Brooker US. Patent 1,950,876, issued Mar. 13, 1934; White US. Patent 1,990,681, issued Feb. 12, 1935; Kostlowsky US. Patent 2,107,379, issued Feb. 8, 1938; Brooker US. Patent 2,112,140, issued Mar. 22, 1938; Brooker US. Patent 2,202,827 issued July 4, 1940; Brooker US. Patent 2,241,237, issued May 6, 1941; Carroll et al. US. Patent 2,369,646, issued Feb. 20, 1945; Carroll et al. US. Patent 2,369,657, issued Feb. 20, 1945; Van de Straete US. Patent 2,484,536, issued Oct. 11, 1949; Keyes US. Patent 2,486,173, issued Oct. 25, 1949; Van Zandt et al. US. Patent 2,515,913, issued July 18, 1950, Dent et al. U.S. Patent 2,537,880, issued Jan. 9, 1959; Heseltine et al. US. Patent 2,666,761, issued Jan. 19, 1954; Jones US. Patent 2,751,298, issued June 19, 1956; etc.

Cyanine dyes of Formula I in which R combined with R or R to form a bridged structure are described by Kendall US. Patent 2,265,909 issued Dec. 9, 1941. I.G.F. British Patent 483,045 accepted Apr. 7, 1938, etc. Cyanine dyes of Formula I in which R and R are combined to form a bridged structure such as ethylene, trimethylene, etc. are described in Lincoln and Heseltine U.S. Ser. No. 226,757, filed Sept. 27, 1962. The synthesis of 1,2-alkylene imidazole bases and the corresponding cyclammonium quaternary salts is described in Lincoln and Brooker U.S. Ser. No. 226,756, filed Sept. 27, 1962; these intermediates are used to advantage to make other dyes of Formula I by methods well known in the art.

The dyes of Formula II are readily prepared by well known processes for preparing holopolar dyes such as are described by Brooker et al. US. 2,739,964 issued Mar. 27, 1956 and reissued on Mar. 19, 1957, as Re. 24,292. For example, they are prepared to advantage by condensing a quaternary salt having the general formula:

III D wherein R, D, X and Y are as defined previously, with a compound having the formula:

wherein L is as defined previously, preferably by heating in the presence of a basic condensing agent followed by condensing the rnerocar-bocyanine dye formed above, with a cyclammonium quaternary salt having the formula:

wherein R X, Z and m are as defined previously. The intermediate compounds of Formula III are prepared to advantage by quaternizing the corresponding hydrogenated products described in Copeland US. Patent 2,942,- 003, issued June 21, 1960. The intermediates of Formulas IV and V and their preparation are well known in the art having been described in numerous patents.

wherein R, R R R Y and X are as defined previously by heating with a compound having the Formula IV followed by condensing the merocarbocyanine dye formed above with a cyclammonium quaternary salt having the formula:

VII Q X-lIl C --S O E:

wherein X, Q and R are as defined previously.

The invention has been described in detail with particular reference to preferred embodiments thereof but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. A photographic silver halide emulsion containing a supersensitizing combination of (l) a dye compound having the general formula:

and (2) a holopolar dye compound having the general wherein d, m and n each represents an integer of from 1 to 2, R and R each represents an alkyl group of from 1 to 12 carbon atoms, R represents a member selected from the class consisting of the hydrogen atom, an alkyl group of from 1 to 4 carbon atoms, a phenyl group, a naphthyl group, a pyrryl group, an indolyl group, a thieenyl group, a pyridyl group and an anilino group; R and R each represents the hydrogen atom, each of R and R taken together and R and R taken together represent a divalent alkylene group having from 2 to 3 carbon atoms, R and R taken together represent a trimethylene group, R and R taken together represent an o phenylene group, X represents an acid anion, Z and Z each represents the nonmetallic atoms required to complete a 5- to G-membered heterocyclic nucleus, Z represents the nonmetallic atoms required to complete a heterocyclic nucleus selected from the class consisting of a 4,5-dihydronaphtho[l,2-d1thiazole nucleus and a naphtho [1,2-d] thiazole nucleus, D represents the nonmetallic atoms required to complete a 4,5-dihydronaphtho[1,2-d]thiazole nucleus, and L represents the nonmetallic atoms required to complete an acidic nucleus selected from the group consisting of a barbituric acid nucleus, a thiobarbituric acid nucleus, a rhodanine nucleus, a hydantoin nucleus, a thiohydantoin nucleus and a 1,3-cyclobutanedione nucleus.

2. A photographic element comprising a support coated with at least one silver halide emulsion layer containing a supersensitizing combination of (1) a chain-substituted carbocyanine dye having the general formula:

and (2) a holopolar dye compound having the general formula:

wherein d, m and n each represents an integer of from 1 to 2, R and R each represents an alkyl group of from 1 to 12 carbon atoms, R represents a member selected from the class consisting of the hydrogen atom, an alkyl group of from 1 to 4 carbon atoms, a phenyl group, a naphthyl group, a pyrryl group, an indolyl group, a thienyl group, a pyridyl group and an anilino group; R and R each represents the hydrogen atom, each of R and R taken together and R and R taken together represent a divalent alkylene group having from 2 to 3 carbon atoms, R and R taken together represent a trimethylene group, R and R taken together represent an o-phenylene group, X represents an acid anion, Z and Z each represents the nonmetallic atoms required to complete a 5- to 6-membered hetrocyclic nucleus, Z represents the nonmetallic atoms required to complete a heterocyclic nucleus selected from the class consisting of a 4,5-dihydronaphtho[l,2- d]thiazole nucleus and a naphtho[l,2-d1thiazole nucleus, D represents the nonmetallic atoms required to complete a 4,5-dihydronaphtho[l,2-d]thiazole nucleus, and L rep resents the nonmetallic atoms required to complete an acidic nucleus selected from the group consisting of a barbituric acid nucleus, a thiobarbituric acid nucleus, a rhodanine nucleus, a hydantoin nucleus, a thiohydantoin nucleus and a 1,3-cyclobutanedione nucleus.

3. A photographic silver halide emulsion containing a supersensitizing combination (1) a dye compound having the general formula:

and (2) a holopolar dye compound having the general formula:

wherein a, m and n each represents an integer of from 1 to 2, R and R each represents an alkyl group of from 1 to 12 carbon atoms, R represents a member selected from the class consisting of the hydrogen atom, an alkyl group of from 1 to 4 carbon atoms, a phenyl group, a naphthyl group, a pyrrl group, an indolyl group, a thienyl group, a pyridyl group and an anilino group; R and R each represents the hydrogen atom, each of R and R taken together and R and R taken together represent a divalent alkylene group having from 2 to 3 carbon atoms, R and R taken together represent a trimethylene group, R and R taken together represent an o-phenylene group, X represents an acid anion, Z and Z each represents the nonmetallic atoms required to complete a heterocyclic nucleus selected from the class consisting of a thiazole nucleus, a benzothiazole nucleus,

a naphthothiazole nucleus, a thianaphtheno-7,6,4,S- thiazole nucleus, an oxazole nucleus, a benzoxazole nucleus, a naphthoxazole nucleus, a selenazole nucleus, 21 benzoselenazole nucleus, a naphthoselenazole nucleus, a thiazoline nucleus, a 2-quinoline nucleus, a 4-quinoline nucleus, a l-isoquinoline nucleus, a 3-isoquinoline nucleus, an imidazole nucleus, a benzimidazole nucleus, a naphthimidazole nucleus, a 3,3-dialkylindolenine nucleus, and a pyridine nucleus; Q represents the nonmetallic atoms required to complete a naphtho[l,2-d]thiazole nucleus, W represents the nonmetallic atoms required to complete a barbituric acid nucleus, R R and R each represents a member selected from the class consisting of hydrogen, a lower alkyl group, a lower alkoxy group, an aryl group, a halogen atom, the cyano group, a sulfo group, and an alkoyloxy group and an alkoxy carbonyl group.

4. A photographic element comprising a support coated with at least one silver halide emulsion layer containing a supersensitizing combination of (l) a chain-substituted carbocyanine dye having the general formula:

and (2) a holopolar dye compound having the general formula:

wherein d, m and 11 each represents an integer of from 1 to 2, R and R each represents an alkyl group of from 1 to 12 carbon atoms, R represents a member selected from the class consisting of the hydrogen atom, an alkyl group of from 1 to 4 carbon atoms, a phenyl group, a naphthyl group, a pyrryl group, an indolyl group, a thienyl group, a pyridyl group and an anilino group; R and R each represents the hydrogen atom, each of R and R taken together and R and R taken together represent a divalent alkylene group having from 2 to 3 carbon atoms, R and R taken together represent a trimethylene group, R and R taken together represent an o-phenylene group, X represents an acid anion, Z and Z each represents the nonmetallic atoms required to complete a heterocyclic nucleus selected from the class consisting of a thiazole nucleus, a benzothiazole nucleus, a naphthothiazole nucleus, a thianaphtheno-7',6,4,5- th'iazole nucleus, an oxazole nucleus, a benzoXazole nucleus, a naphthoxazole nucleus, 21 selenazole nucleus, a benzoselenazole nucleus, a naphthoselenazole nucleus, a thiazoline nucleus, a 2-quinoline nucleus, a 4-quinoline nucleus, a l-isoquinoline nucleus, a 3-isoquinoline nucleus, an imidazole nucleus, a benzimidazole nucleus, a naphthimidazole nucleus, a 3,3-dialkylindolenine nucleus, and a pyridine nucleus, Q represents the nonmetallic atoms required to complete a naphtho[1,2-d]thiazole nucleus, W represents the nonmetallic atoms required to complete a barbituric acid nucleus, R R and R each represents a member selected from the class consisting of hydrogen, a lower alkyl group, a lower alkoxy group, an aryl group, a halogen atom, the cyano group, a sulfo group, and an alkoyloxy group and an alkoxy carbonyl group.

5. A photographic silver halide emulsion containing a supersensitizing combination of claim 3 in which the holopolar carbocyanine dye is 1,3-diethyl-5-[(1-ethyl-4,5- dihydro 2(1H) naphtho[l,2 d]thiazolylidene)(l- 16 methyl 2( 1H) naphtho[l,2 d]thiazolylidene) isopropylidene1barbituric acid.

6. A photographic silver halide emulsion containing a supersensitizing combination of claim 3 in which the holopolar carbocyanine dye is l,3-diethyl-5-[(1-ethyl-4,5- dihydro 2(1H) naphtho[1,2 d]thiazolylidene)(lethyl 2(1H) naphtho[1,2 d] thiazolylidene) isopropylidene]barbituric acid.

7. A photographic silver halide emulsion containing a supersensitizing combination of claim 3 in which the holopolar carbocyanine dye, is l,3-diethyl-5-[(l-ethyl-4,5-dihydro 2(11-1) naphtho[1,2 d]thiazolylidene) (3 ethyl- 2(3H) naphtho [2,l-d]thiazolylidene)-isopropylidene] barbituric acid.

8. A photographic silver halide emulsion containing a supersensitizing combination of 3,3'-dimethyl-9-phenyl- 4,5,45-dibenzothiacarbocyanine bromide with 1,3-diethyl 5[(1-ethyl-4,5-dihydro-2(1H)-naphtho[ 1,2-d]thiazolylidene) (1-methyl-2(1H) naphtho[1,2 d]thiazolylidene)- isopropylidene]barbituric acid.

9. A photographic silver halide emulsion containing a supersensitizing combination of 3,3-dimethyl 9 phenyl- 4,5,4,5-dibenzothiacarbocyanine bromo with 1,3,-diethyl-5-[(1-ethyl-4,5-dihydro 2( lH)-naphtho[1,2-d]thiazo lylidene) (3-ethyl 2(3H)-naphtho[2,1-d]thiazolylidene)- isopropylidene]barbituric acid.

10. A photographic silver halide emulsion containing a supersensitizing combination of 3,3'-dimethyl-9-ethyl-oxacarbocyanine iodide with 1,3-diethy1-5-[(1-ethyl-4,5-dihydro 2(1H) naphtho[l,2 d]thiazolylidene) (1 methyl- 2(1H)-naphtho-[l,2 d]thiazolylidene) isopropylidene] barbituric acid.

11. A photographic silver halide emulsion containing a supersensitizing combination of 8,l0-ethylene-3,3'-dimethyl-thiacarbocyanine iodide with 1,3-diethyl-5-](l-ethyl- 4,5-dihydro 2(1H) naphth0[1,2 d]thiazolylidene)(1 methyl 2(lH)-naphtho[1,2-d]thiazolylidene)-isopropyl idene]barbituric acid.

12. A photographic silver halide emulsion containing a supersensitizing combination of 3,3'-dimethyl-5,5'-9-triphenylthiacarbocyanine p-toluenesulfonate with 1,3-diethyl-5-[ (1-ethyl-4,5-dihydro 2( 1H -naphtho 1,2-d]thiazolylidene) (3-ethyl 2(3H)-naphtho[2,1-d]thiazolylidene)- isopropylidene]barbituric acid.

13. A photographic element comprising a support coated with at least one layer containing a supersensitizing combination of claim 4 in which the holopolar carbocyanine dye is 1,3-diethyl-5-[(l-ethyl-4,5-dihydro-2(1H) naphtho-[1,2-d]thiazolylidene) (1-methyl-2(1H)-naphtho- [1,2-d] thiazolylidene) isopropylidene] barbituric acid.

14. A photographic element comprising a support coated with at least one layer containing a supersensitizing combination of claim 4 in which the holopolar carbocyanine dye is 1,3-diethyl-5-[(1-ethyl-4,5-dihydro-2(1H) naphtho[1,2 d]thiazolylidene) (1 ethyl-2(lH)-naphtho- [1,2-d] thiazolylidene isopropylidene] barbituric acid.

15. A photographic element comprising a support coated with at least one layer containing a supersensitizing combination of claim 4 in which the holopolar carbocyanine dye is 1,3-diethyl-5-[(1-ethyl-4,5-dihydro-2( 1H) naphtho[1,2 d]thiazolylidene) (3 ethyl-2(3H)-naphtho- [2, l-d] thiazolylidene isopropylidene] barbituric acid.

16. A photographic element comprising a support coated With at least one layer containing a photographic silver halide emulsion containing a supersensitizing combination of 3,3'-dimethyl-9-phenyl-4,5,4',5'-dibenzothiacarbocyanine bromide with 1,3-diethyl-5-[(1-ethyl-4,5-dihydro 2(1H)-naphtho[1,2-d]thiazolylidene) l-methyl-Z- (1H)-naphtho[ 1,2 d] -thiazolylidene)isopropylidene] barbituric acid.

17. A photographic element comprising a support coated with at least one layer containing a photographic silver halide emulsion containing a supersensitizing combination of 3,3-dimethyl-9-phenyl-4,5,4',5-dibenzothiacarbocyanine bromide with l,3-diethyl-5-[(l-ethyl-4,5-dil7 hydro 2(lH)-naphtho[1,2-d]thiazolylidene) (3-ethyl 2- (3H)-naphtho[2,l d]thiazolylidene)isopropylideneJbarbituric acid.

18. A photographic element comprising a support coated with at least one layer containing a photographic silver halide emulsion containing a supersensitizing combination of 3,3'-dimethyl-9-ethyl-oxacarbocyanine iodide with 1,3-diethyl 5 -[(1-ethyl-4,5 -dihydro-2(1H)-naphtho- [1,2 d] thiazolylidene)( 1- methyl-2(1H)-naphtho[1,2-d] thiazolylidene) isopropylidene] barbituric acid.

19- A photographic element comprising a support coated with at least one layer containing a photographic silver halide emulsion containing a supersensitizing combination of 8,10-ethy1ene-3,3-dimethylthiacarbocyanine idode with 1,3-diethyl 5 [(1-ethyl 4,5-dihydro-2(1H) naphtho[1,2 d]thiazolylidene) (1-methyl-2(lH)-naphtho- [1,2-d] thiazolylidene) isopropylidene] barbituric acid.

20. A photographic element comprising a support coated with at least one layer containing a photographic silver halide emulsion containing a supersensitizing combination of 3,3'-dimethyl-5,5',9-triphenylthiocarbocyanine p-toluene-sulfonate with 1,3-diethy1-5-[(1-ethyl-4,5-dihydro-2(1H) naphtho[1,2 dJthiazolylidene) (3 ethyl 2- (3H)-naphtho[2,1 d] thiazolylidene)isopropylidene]barbituric acid.

References Cited UNITED STATES PATENTS 2,704,714 3/1955 Carroll et a1. 96104 2,704,715 3/1955 Carroll et a1 96104 2,704,720 3/1955 Jones 96104 J. TRAVIS BROWN, Primary Examiner.

US. Cl. X.R. 96105 mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No- 3, 4-3 :3 Dated March 11 19 9 Inventor(s) Jean E. Jones 8c Norman W. Kalenda (USN 1458,06?)

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1 line 18, "heterocyclc" should read -heterocyclio--. Column 1h, approximate line 10, that portion of the formula reading Z should read ,2

z I I approximate l ine L B, that portion of the formula in the right half thereof reading ,2 should read ,Z

Column 15, line 50, "R should read -R Column 16, line 11 after "dye", delete line 23, "bromo should read --bromide-- line 35, that portion of formula reading "1 ,3-diethyl-27H should read --1 ,3-diethyl5-/ (1 line L .O, that portion of formula reading "5,5' -9-" should read --5,5' ,9- lines 148-119; that portion of formula reading "-2(1H)naphtho" should read 2(1H)-naphtho; lines EL -55, that portion of formula reading "-2 H)naphtho" should read -2(1H)-naphtho; lines 60-61 that portion of formula reading "-2(1H)naphtho" should read -2(1H)-naphtho Column 17, line 15, 'idode" should read --iodide--; lines 15-16, that portion of formula reading "-2(1H)naphtho" should read -2(1H)-naphtho Signed and sealed this 6th day of July 1971.

.(SEAL) Attest:

l. EDWARD M.FLE'I'GHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Conmissioner of Patents 

